The present invention relates in general to paperboard or cardboard packages having locking flaps associated therewith, and more particularly to sleeve or wrapper type packages of cardboard, paperboard or similar material, having a flap and a pocket for receiving the flap to hold the sleeve or wrapper type package in closed condition.
Heretofore, packages made of cardboard, paperboard or the like of the sleeve or wrapper type designed to extend around and form a retaining sleeve or wrap about an article or articles to be packaged have provided for locking opposite end portions of the blank together, but these have customarily employed a slit in one end portion of the paperboard blank and a tab formed in the opposite end portion of the paperboard blank to form a tab and slit arrangement for retaining the package in closed condition. Examples of such as tab and slit arrangement may be found in U.S. Pat. Nos. 4,732,316 to Oliff, 3,499,597 to Katzman which disclose a suspendable carton with a closure structure or display package comprising tabs which extend through or into slots to retain the closure structure or package in closed condition. With such a construction, the slit cut in the paperboard weakens the package, permitting it to tear readily in the zone in which the slit occurs, and this type of locking arrangement sometimes creates difficulties in properly engaging the tab in the slit in a consistent manner.
Glue panels have also been frequently resorted to in such sleeve or wrapper type packages, wherein flaps are folded into engagement with a mating or companion panel or flap having an adhesive surface or glue applied thereto to fasten the companion panels or flaps together. U.S. Pat. Nos. 3,312,337 to Martin and 4,549,654 to Tiesman are typical of this construction.
An object of the present invention is the provision of a sleeve or wrapper type package which is closed by a novel positive locking arrangement, wherein a folded flap is tucked into a pocket formed by a pocket panel, such that when the flap is inserted into the pocket, edges of the tuck flap automatically engage confronting edges of matching tabs inside the pocket to achieve locking of the flap within the pocket. This lock panel can be located in the center of the top surface of the package, thus providing a panel for a hang tab, a handle, graphics display, or other uses.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.